Update.

	* timezone/antarctica: Update from tzdata2000a.
	* timezone/asia: Likewise.
	* timezone/australasia: Likewise.
	* timezone/backward: Likewise.
	* timezone/northamerica: Likewise.
	* timezone/southamerica: Likewise.
	* timezone/zone.tab: Likewise.

7 files changed, 188 insertions, 68 deletions

diff --git a/timezone/antarctica b/timezone/antarctica
index 82d8299..38bcd89 100644
--- a/timezone/antarctica
+++ b/timezone/antarctica
@@ -1,9 +1,9 @@
-# @(#)antarctica	7.16
+# @(#)antarctica	7.17
 
-# From Paul Eggert (1999-03-22):
+# From Paul Eggert (1999-11-15):
 # To keep things manageable, we list only locations occupied year-round; see
-# <a href="http://www.delm.tas.gov.au/comnap/members.html">
-# Antarctic Activities of Member Nations of the Antarctic Treaty (1996-05-24)
+# <a href="http://www.comnap.aq/comnap/comnap.nsf/P/Stations/">
+# COMNAP - Stations and Bases
 # </a>
 # and
 # <a href="http://www.spri.cam.ac.uk/bob/periant.htm">
@@ -35,18 +35,24 @@ Rule	ChileAQ	1999	max	-	Oct	Sun>=9	0:00	1:00	S
 Rule	ChileAQ	2000	max	-	Mar	Sun>=9	0:00	0	-
 
 
-# Argentina - 6 year-round bases
-# General Belgrano II
-# 5 others
+# Argentina - year-round bases
+# Belgrano II, Confin Coast, -770227-0343737, since 1972-02-05
+# Esperanza, San Martin Land, -6323-05659, since 1952-12-17
+# Jubany, Potter Peninsula, King George Island, -6414-0602320, since 1982-01
+# Marambio, Seymour I, -6414-05637, since 1969-10-29
+# Orcadas, Laurie I, -6016-04444, since 1904-02-22
+# San Martin, Debenham I, -6807-06708, since 1951-03-21
+#	(except 1960-03 / 1976-03-21)
 
 # Australia - territories
 # Heard Island, McDonald Islands (uninhabited)
 #	previously sealers and scientific personnel wintered
 #
 # year-round bases
-# Casey, Bailey Peninsula, since 1969
-# Davis, Vestfold Hills, since 1957-01-13 (except 1964-11 - 1969-02)
-# Mawson, Holme Bay, since 1954-02-13
+# Casey, Bailey Peninsula, -6617+11032, since 1969
+# Davis, Vestfold Hills, -6835+07759, since 1957-01-13
+#	(except 1964-11 - 1969-02)
+# Mawson, Holme Bay, -6736+06253, since 1954-02-13
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Antarctica/Casey	0	-	___	1969
 			8:00	-	WST	# Western (Aus) Standard Time
@@ -70,15 +76,16 @@ Zone Antarctica/Mawson	0	-	___	1954 Feb 13
 # Brazil - year-round base
 # Ferraz, King George Island, since 1983/4
 
-# Chile - 4 year-round bases
+# Chile - year-round bases
+# Escudero, South Shetland Is, -621157-0585735, since 1994
+# Frei, King George Is, -6214-05848, since 1969
+# O'Higgins, Antarctic Peninsula, -6319-05704, since 1948-02
+# Prat, -6230-05941
 
 # China - year-round bases
 # Great Wall, King George Island, since 1985-02-20
 # Zhongshan, Larsemann Hills, Prydz Bay, since 1989-02-26
 
-# Finland - year-round base
-# Aboa, Queen Maud Land, since 1988
-
 # France - year-round bases
 #
 # From Antoine Leca <Antoine.Leca@Renault.FR> (1997-01-20):
@@ -103,7 +110,7 @@ Zone Indian/Kerguelen	0	-	___	1950	# Port-aux-Francais
 			5:00	-	TFT	# ISO code TF Time
 #
 # year-round base in the main continent
-# Dumont-d'Urville, Terre Adelie (Adelie Land), -6640+14001, since 1956-11
+# Dumont-d'Urville, Ile des Petrels, -6640+14001, since 1956-11
 #
 # Another base at Port-Martin, 50km east, began operation in 1947.
 # It was destroyed by fire on 1952-01-14.
@@ -172,11 +179,11 @@ Rule	NZAQ	1990	max	-	Mar	Sun>=15	2:00s	0	S
 # Peter I Island (never inhabited)
 
 # Poland - year-round base
-# Arctowski, King George Island, since 1977
+# Arctowski, King George Island, -620945-0582745, since 1977
 
 # Russia - year-round bases
-# Bellingshausen, King George Island
-# Mirny
+# Bellingshausen, King George Island, -621159-0585337, since 1968-02-22
+# Mirny, Davis coast, -6633+09301, since 1956-02
 # Molodezhnaya
 # Novolazarevskaya
 # Vostok
@@ -198,11 +205,12 @@ Rule	NZAQ	1990	max	-	Mar	Sun>=15	2:00s	0	S
 #	and a garrison was deployed briefly
 #
 # year-round bases
+# Bird Island, South Georgia, -5400-03803, since 1983
 # Halley, Coates Land, -7535-2619, since 1956-01-06
 # Rothera, Adelaide Island, -6734-6808, since 1976-12-01
 
 # Uruguay - year round base
-# Artigas, King George Island
+# Artigas, King George Island, -9621104-0585107
 
 # USA - year-round bases
 #
diff --git a/timezone/asia b/timezone/asia
index 8a167d0..7f63389 100644
--- a/timezone/asia
+++ b/timezone/asia
@@ -1,4 +1,4 @@
-# @(#)asia	7.50
+# @(#)asia	7.51
 
 # This data is by no means authoritative; if you think you know better,
 # go ahead and edit the file (and please send any changes to
@@ -84,8 +84,7 @@ Zone	Asia/Kabul	4:36:48 -	LMT	1890
 # <edd@AIC.NET> reported (1996-05-04) that Yerevan probably wouldn't use DST
 # in 1996, though it did use DST in 1995.  IATA SSIM (1991/1998) reports that
 # Armenia switched from 3:00 to 4:00 in 1998 and observed DST after 1991,
-# but started switching at 3:00s in 1998.  IATA SSIM (1999-02) reports
-# that they switch one day later in 2001 (i.e. on Mondays).
+# but started switching at 3:00s in 1998.
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Yerevan	2:58:00 -	LMT	1924 May  2
 			3:00	-	YERT	1957 Mar    # Yerevan Time
@@ -235,8 +234,7 @@ Rule	HK	1979	1980	-	May	Sun>=8	3:30	1:00	S
 Rule	HK	1979	1980	-	Oct	Sun>=16	3:30	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Hong_Kong	7:36:36 -	LMT	1904 Oct 30
-			8:00	HK	HK%sT	1997 Jul  1 # return to China
-			8:00	PRC	C%sT
+			8:00	HK	HK%sT
 
 
 ###############################################################################
@@ -853,31 +851,62 @@ Zone	Indian/Maldives	4:54:00 -	LMT	1880	# Male
 			5:00	-	MVT		# Maldives Time
 
 # Mongolia
+
 # Shanks says that Mongolia has three time zones, but usno1995 and the CIA map
 # Standard Time Zones of the World (1997-01)
 # both say that it has just one.
-# Let's comment out the western and eastern Mongolian time zones
-# till we know what their principal towns are.
+
+# From Oscar van Vlijmen (1999-12-11):
+# <a href="http://www.mongoliatourism.gov.mn/general.htm">
+# General Information Mongolia
+# </a> (1999-09)
+# "Time: Mongolia has two time zones. Three westernmost provinces of
+# Bayan-Ulgii, Uvs, and Hovd are one hour earlier than the capital city, and
+# the rest of the country follows the Ulaanbaatar time, which is UTC/GMT plus
+# eight hours."
+
+# From Rives McDow (1999-12-13):
+# Mongolia discontinued the use of daylight savings time in 1999; 1998
+# being the last year it was implemented.  The dates of implementation I am
+# unsure of, but most probably it was similar to Russia, except for the time
+# of implementation may have been different....
+# Some maps in the past have indicated that there was an additional time
+# zone in the eastern part of Mongolia, including the provinces of Dornod,
+# Suhbaatar, and possibly Khentij.
+
+# From Paul Eggert (1999-12-15):
+# For now, we'll comment out the east zone (Choybalsan)
+# and use Shanks's and the IATA's data for the daylight-saving rules.
+# Naming and spelling is tricky in Mongolia.
+# We'll use Hovd (also spelled Chovd and Khovd) to represent the west zone;
+# the capital of the Hovd province is sometimes called Hovd, sometimes Dund-Us,
+# and sometimes Jirgalanta (with variant spellings), but the name Hovd
+# is good enough for our purposes.
+
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Mongol	1981	1984	-	Apr	1	0:00	1:00	S
 Rule	Mongol	1981	1984	-	Oct	1	0:00	0	-
 Rule	Mongol	1985	1990	-	Mar	lastSun	2:00	1:00	S
 Rule	Mongol	1985	1990	-	Sep	lastSun	3:00	0	-
-Rule	Mongol	1991	max	-	Mar	lastSun	0:00	1:00	S
+Rule	Mongol	1991	1998	-	Mar	lastSun	0:00	1:00	S
 Rule	Mongol	1991	1995	-	Sep	lastSun	0:00	0	-
 # IATA SSIM (1996-09) says 1996-10-25; go with Shanks.
 Rule	Mongol	1996	only	-	Oct	lastSun	0:00	0	-
-Rule	Mongol	1997	max	-	Sep	lastSun	0:00	0	-
+Rule	Mongol	1997	1998	-	Sep	lastSun	0:00	0	-
+# IATA SSIM (1999-09) says Mongolia no longer observes DST.
+
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
-#Zone	Asia/Dariv	6:14:32 -	LMT	1905 Aug
-#			6:00	-	DART	1978	# Dariv Time
-#			7:00	Mongol	DAR%sT
-Zone	Asia/Ulan_Bator	7:07:32 -	LMT	1905 Aug
-			7:00	-	ULAT	1978	# Ulan Bator Time
+Zone	Asia/Hovd	6:06:36 -	LMT	1905 Aug
+			6:00	-	HOVT	1978	# Hovd Time
+			7:00	Mongol	HOV%sT
+Zone	Asia/Ulaanbaatar 7:07:32 -	LMT	1905 Aug
+			7:00	-	ULAT	1978	# Ulaanbaatar Time
 			8:00	Mongol	ULA%sT
-#Zone Asia/Baruun-Urt	7:33:00 -	LMT	1905 Aug
-#			8:00	-	BART	1978	# Baruun-Urt Time
-#			9:00	Mongol	BAR%sT
+# We're not sure about this entry yet, so we'll omit it for now.
+#Zone Asia/Choybalsan	7:38:00 -	LMT	1905 Aug
+#			8:00	-	CHOT	1978	# Choybalsan Time
+#			9:00	Mongol	CHO%sT	19??
+#			8:00	Mongol	ULA%sT
 
 # Nepal
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
@@ -1097,7 +1126,8 @@ Rule	Syria	1993	only	-	Mar	26	0:00	1:00	S
 Rule	Syria	1993	only	-	Sep	25	0:00	0	-
 # IATA SSIM (1998-02) says 1998-04-02;
 # (1998-09) says 1999-03-29 and 1999-09-29; (1999-02) says 1999-04-02,
-# 2000-04-02, and 2001-04-02; ignore all these claims and go with Shanks.
+# 2000-04-02, and 2001-04-02; (1999-09) says 2000-03-31 and 2001-03-31;
+# ignore all these claims and go with Shanks.
 Rule	Syria	1994	1996	-	Apr	 1	0:00	1:00	S
 Rule	Syria	1994	max	-	Oct	 1	0:00	0	-
 Rule	Syria	1997	1998	-	Mar	lastMon	0:00	1:00	S
diff --git a/timezone/australasia b/timezone/australasia
index a841574..ebe2951 100644
--- a/timezone/australasia
+++ b/timezone/australasia
@@ -1,4 +1,4 @@
-# @(#)australasia	7.53
+# @(#)australasia	7.54
 # This file also includes Pacific islands.
 
 # Notes are at the end of this file
@@ -177,9 +177,6 @@ Zone Australia/Lord_Howe 10:36:20 -	LMT	1895 Feb
 # The Australian Bureau of Meteorology FAQ
 # </a> (1999-09-27) writes that Macquarie Island follows Tasmanian practice
 # irrespective of any local use of DST.  This is unclear; ignore it for now.
-#
-# Manihiki, Penrhyn, Rakehanga
-# no information
 
 # Christmas
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
@@ -348,7 +345,7 @@ Zone	Pacific/Norfolk	11:11:52 -	LMT	1901		# Kingston
 			11:12	-	NMT	1951	# Norfolk Mean Time
 			11:30	-	NFT		# Norfolk Time
 
-# Palau
+# Palau (Belau)
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Palau	8:57:56 -	LMT	1901		# Koror
 			9:00	-	PWT	# Palau Time
@@ -854,8 +851,7 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 
 ###############################################################################
 
-# New Zealand, from Elz' asia 1.1
-# Elz says "no guarantees"
+# New Zealand
 
 # From Mark Davies (1990-10-03):
 # the 1989/90 year was a trial of an extended "daylight saving" period.
@@ -896,6 +892,7 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 
 ###############################################################################
 
+
 # Fiji
 
 # Howse writes (p 153) that in 1879 the British governor of Fiji
@@ -907,6 +904,9 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # until 0300 local time 1999-02-28.  Each year the DST period will 
 # be from the first Sunday in November until the last Sunday in February.
 
+# From Paul Eggert (2000-01-08):
+# IATA SSIM (1999-09) says DST ends 0100 local time.  Go with McDow.
+
 # From the BBC World Service (1998-10-31 11:32 UTC):
 # The Fijiian government says the main reasons for the time change is to
 # improve productivity and reduce road accidents.  But correspondents say it
@@ -914,10 +914,12 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # islands in the effort to attract tourists to witness the dawning of the new
 # millenium.
 
+
 # Johnston
 
 # Johnston data is from usno1995.
 
+
 # Kiribati
 
 # From Paul Eggert (1996-01-22):
@@ -925,6 +927,7 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # ``declared it the same day throught the country as of Jan. 1, 1995''
 # as part of the competition to be first into the 21st century.
 
+
 # Kwajalein
 
 # In comp.risks 14.87 (26 August 1993), Peter Neumann writes:
@@ -933,6 +936,7 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # respect to the International Date Line, to rejoin its fellow islands,
 # going from 11:59 p.m. Thursday to 12:00 m. Saturday in a blink.
 
+
 # N Mariana Is, Guam
 
 # Howse writes (p 153) ``The Spaniards, on the other hand, reached the
@@ -940,6 +944,7 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # (now called the Marianas) kept American date for quite some time.
 # Ignore this for now, as we have no hard data.  See also Asia/Manila.
 
+
 # Micronesia
 
 # Alan Eugene Davis <adavis@kuentos.guam.net> writes (1996-03-16),
@@ -957,6 +962,7 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # that Truk and Yap are UTC+10, and Ponape and Kosrae are UTC+11.
 # We don't know when Kosrae switched from UTC+12; assume January 1 for now.
 
+
 # Pitcairn
 
 # From Rives McDow (1999-11-08):
@@ -980,6 +986,7 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # Pacific Standard Time. They used to be 1/2 hour different from us here in
 # Sacramento but it was changed a couple of years ago.
 
+
 # Samoa
 
 # Howse writes (p 153, citing p 10 of the 1883-11-18 New York Herald)
@@ -988,6 +995,7 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # ordaining -- by a masterpiece of diplomatic flattery -- that
 # the Fourth of July should be celebrated twice in that year.''
 
+
 # Tonga
 
 # From Paul Eggert (1996-01-22):
@@ -1057,3 +1065,31 @@ Zone	Pacific/Wallis	12:15:20 -	LMT	1901
 # From Rives McDow (1999-10-06):
 # Tonga started its Daylight Saving on Saturday morning October 2nd at 0200am.
 # Daylight Saving ends on April 16 at 0300am which is Sunday morning.
+
+
+###############################################################################
+
+# The International Date Line
+
+# From Gwillim Law (2000-01-03):
+# 
+# The International Date Line is not defined by any international standard,
+# convention, or treaty.  Mapmakers are free to draw it as they please.
+# Reputable mapmakers will simply ensure that every point of land appears on
+# the correct side of the IDL, according to the date legally observed there.
+#
+# When Kiribati adopted a uniform date in 1995, thereby moving the Phoenix and
+# Line Islands to the west side of the IDL (or, if you prefer, moving the IDL
+# to the east side of the Phoenix and Line Islands), I suppose that most
+# mapmakers redrew the IDL following the boundary of Kiribati.  Even that line
+# has a rather arbitrary nature.  The straight-line boundaries between Pacific
+# island nations that are shown on many maps are based on an international
+# convention, but are not legally binding national borders.
+#
+# An Anglo-French Conference on Time-Keeping at Sea (June, 1917) agreed that
+# legal time on the high seas would be zone time, i.e., the standard time at
+# the nearest meridian that is a multiple of fifteen degrees.  The date is
+# governed by the IDL; therefore, even on the high seas, there may be some
+# places as late as fourteen hours later than UTC.  And, since the IDL is not
+# an international standard, there are some places on the high seas where the
+# correct date is ambiguous.
diff --git a/timezone/backward b/timezone/backward
index 23b76cb..cc0caa8 100644
--- a/timezone/backward
+++ b/timezone/backward
@@ -1,4 +1,4 @@
-# @(#)backward	7.16
+# @(#)backward	7.17
 
 # This file provides links between current names for time zones
 # and their old names.  Many names changed in late 1993.
@@ -9,6 +9,7 @@ Link	America/Indianapolis	America/Fort_Wayne
 Link	America/Indiana/Knox	America/Knox_IN
 Link	America/St_Thomas	America/Virgin
 Link	Asia/Jerusalem		Asia/Tel_Aviv
+Link	Asia/Ulaanbaatar	Asia/Ulan_Bator
 Link	Australia/Sydney	Australia/ACT
 Link	Australia/Sydney	Australia/Canberra
 Link	Australia/Lord_Howe	Australia/LHI
@@ -39,6 +40,7 @@ Link	America/Havana		Cuba
 Link	Africa/Cairo		Egypt
 Link	Europe/Dublin		Eire
 Link	Europe/London		GB
+Link	Europe/London		GB-Eire
 Link	Etc/GMT+0		GMT+0
 Link	Etc/GMT-0		GMT-0
 Link	Etc/GMT0		GMT0
diff --git a/timezone/northamerica b/timezone/northamerica
index 443e8db..ff7fb52 100644
--- a/timezone/northamerica
+++ b/timezone/northamerica
@@ -1,4 +1,4 @@
-# @(#)northamerica	7.49
+# @(#)northamerica	7.50
 # also includes Central America and the Caribbean
 
 # This data is by no means authoritative; if you think you know better,
@@ -952,6 +952,14 @@ Zone America/Dawson_Creek -8:00:56 -	LMT	1884
 # their senses", but the locals evidently don't see any problem with
 # the current state of affairs.
 
+# From Michaela Rodrigue, writing in the
+# <a href="http://www.nunatsiaq.com/archives/nunavut991130/nvt91119_17.html">
+# Nunatsiaq News (1999-11-19)</a>:
+# Clyde River, Pangnirtung and Sanikiluaq now operate with two time zones,
+# central - or Nunavut time - for government offices, and eastern time
+# for municipal offices and schools....  Igloolik [was similar but then]
+# made the switch to central time on Saturday, Nov. 6.
+
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	NT_YK	1918	only	-	Apr	14	2:00	1:00	D
 Rule	NT_YK	1918	only	-	Oct	27	2:00	0	S
@@ -1079,6 +1087,12 @@ Zone America/Dawson	-9:17:40 -	LMT	1900 Aug 20
 # The State of Quintana Roo has reverted back to central STD and DST times
 # (i.e. UTC -0600 and -0500 as of 1998-08-02).
 
+# From Rives McDow (2000-01-10):
+# Effective April 4, 1999 at 2:00 AM local time, Sonora changed to the time
+# zone 5 hours from the International Date Line, and will not observe daylight
+# savings time so as to stay on the same time zone as the southern part of
+# Arizona year round.
+
 # From Shanks:
 # Rule	NAME	FROM	TO	TYPE	IN	ON	AT	SAVE	LETTER/S
 Rule	Mexico	1939	only	-	Feb	5	0:00	1:00	D
@@ -1120,7 +1134,19 @@ Zone America/Chihuahua	-7:04:20 -	LMT	1921 Dec 31 23:55:40
 			-6:00	Mexico	C%sT	1998
 			-6:00	-	CST	1998 Apr Sun>=1 3:00
 			-7:00	Mexico	M%sT
-# S Baja California, Nayarit, Sinaloa, Sonora
+# Sonora
+Zone America/Hermosillo	-7:23:52 -	LMT	1921 Dec 31 23:36:08
+			-7:00	-	MST	1927 Jun 10 23:00
+			-6:00	-	CST	1930 Nov 15
+			-7:00	-	MST	1931 May  1 23:00
+			-6:00	-	CST	1931 Oct
+			-7:00	-	MST	1932 Mar 30 23:00
+			-6:00	-	CST	1942 Apr
+			-7:00	-	MST	1949 Jan 14
+			-8:00	-	PST	1970
+			-7:00	Mexico	M%sT	1999
+			-7:00	-	MST
+# S Baja California, Nayarit, Sinaloa
 Zone America/Mazatlan	-7:05:40 -	LMT	1921 Dec 31 23:54:20
 			-7:00	-	MST	1927 Jun 10 23:00
 			-6:00	-	CST	1930 Nov 15
@@ -1261,7 +1287,7 @@ Rule	Cuba	1996	only	-	Oct	 6	0:00s	0	S
 Rule	Cuba	1997	only	-	Oct	12	0:00s	0	S
 Rule	Cuba	1998	1999	-	Mar	lastSun	0:00s	1:00	D
 Rule	Cuba	1998	max	-	Oct	lastSun	0:00s	0	S
-Rule	Cuba	2000	max	-	Apr	 1	0:00s	1:00	D
+Rule	Cuba	2000	max	-	Apr	Sun>=1	0:00s	1:00	D
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	America/Havana	-5:29:28 -	LMT	1890
diff --git a/timezone/southamerica b/timezone/southamerica
index 3b647b1..bd020a7 100644
--- a/timezone/southamerica
+++ b/timezone/southamerica
@@ -1,4 +1,4 @@
-# @(#)southamerica	7.33
+# @(#)southamerica	7.34
 
 # This data is by no means authoritative; if you think you know better,
 # go ahead and edit the file (and please send any changes to
@@ -80,12 +80,12 @@ Rule	Arg	1963	only	-	Dec	15	0:00	1:00	S
 Rule	Arg	1964	1966	-	Mar	 1	0:00	0	-
 Rule	Arg	1964	1966	-	Oct	15	0:00	1:00	S
 Rule	Arg	1967	only	-	Apr	 1	0:00	0	-
-Rule	Arg	1967	1968	-	Oct	Sun<=7	0:00	1:00	S
-Rule	Arg	1968	1969	-	Apr	Sun<=7	0:00	0	-
+Rule	Arg	1967	1968	-	Oct	Sun>=1	0:00	1:00	S
+Rule	Arg	1968	1969	-	Apr	Sun>=1	0:00	0	-
 Rule	Arg	1974	only	-	Jan	23	0:00	1:00	S
 Rule	Arg	1974	only	-	May	 1	0:00	0	-
-Rule	Arg	1974	1976	-	Oct	Sun<=7	0:00	1:00	S
-Rule	Arg	1975	1977	-	Apr	Sun<=7	0:00	0	-
+Rule	Arg	1974	1976	-	Oct	Sun>=1	0:00	1:00	S
+Rule	Arg	1975	1977	-	Apr	Sun>=1	0:00	0	-
 Rule	Arg	1985	only	-	Nov	 2	0:00	1:00	S
 Rule	Arg	1986	only	-	Mar	14	0:00	0	-
 Rule	Arg	1986	1987	-	Oct	25	0:00	1:00	S
@@ -108,6 +108,15 @@ Rule	Arg	1989	1992	-	Oct	Sun>=15	0:00	1:00	S
 # time corrections was derogated and no more modifications
 # to the time zones (for daylight saving) are now made.
 #
+# From Rives McDow (2000-01-10):
+# On October 3, 1999, 0:00 local, Argentina implemented daylight savings time,
+# which did not result in the switch of a time zone, as they stayed 9 hours
+# from the International Date Line.  On March 5, 2000, at 0:00 local time,
+# Argentina will come off daylight savings time, which will bring them to 8
+# hours from the International Date Line.
+Rule	Arg	1999	max	-	Oct	Sun>=1	0:00	1:00	S
+Rule	Arg	2000	max	-	Mar	Sun>=1	0:00	0	-
+#
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 #
 # Buenos Aires (BA), Distrito Federal (DF), Santa Cruz (SC),
@@ -115,26 +124,29 @@ Rule	Arg	1989	1992	-	Oct	Sun>=15	0:00	1:00	S
 Zone America/Buenos_Aires -3:53:48 -	LMT	1894 Nov
 			-4:16:44 -	CMT	1920 May    # Cordoba Mean Time
 			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct 5
-			-3:00	Arg	AR%sT
+			-4:00	Arg	AR%sT	1969 Oct  5
+			-3:00	Arg	AR%sT	1999 Oct  3 0:00
+			-4:00	Arg	AR%sT
 #
 # Santa Fe (SF), Entre Rios (ER), Corrientes (CN), Misiones (MN), Chaco (CC),
 # Formosa (FM), La Pampa (LP), Chubut (CH)
 Zone America/Rosario	-4:02:40 -	LMT	1894 Nov
 			-4:16:44 -	CMT	1920 May
 			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct 5
+			-4:00	Arg	AR%sT	1969 Oct  5
 			-3:00	Arg	AR%sT	1991 Jul
-			-3:00	-	ART
+			-3:00	-	ART	1999 Oct  3 0:00
+			-4:00	Arg	AR%sT
 #
 # Cordoba (CB), Santiago del Estero (SE), Salta (SA), Tucuman (TM), La Rioja (LR), San Juan (SJ), San Luis (SL),
 # Neuquen (NQ), Rio Negro (RN)
 Zone America/Cordoba	-4:16:44 -	LMT	1894 Nov
 			-4:16:44 -	CMT	1920 May
 			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct 5
+			-4:00	Arg	AR%sT	1969 Oct  5
 			-3:00	Arg	AR%sT	1990 Jul
-			-3:00	-	ART
+			-3:00	-	ART	1999 Oct  3 0:00
+			-4:00	Arg	AR%sT
 #
 # Jujuy (JY)
 Zone America/Jujuy	-4:21:12 -	LMT	1894 Nov
@@ -145,17 +157,19 @@ Zone America/Jujuy	-4:21:12 -	LMT	1894 Nov
 			-4:00	-	WART	1991 Oct  6
 			-4:00	1:00	WARST	1992 Mar 15
 			-4:00	-	WART	1992 Oct 18
-			-3:00	-	ART
+			-3:00	-	ART	1999 Oct  3 0:00
+			-4:00	Arg	AR%sT
 #
 # Catamarca (CT)
 Zone America/Catamarca	-4:23:08 -	LMT	1894 Nov
 			-4:16:44 -	CMT	1920 May
 			-4:00	-	ART	1930 Dec
-			-4:00	Arg	AR%sT	1969 Oct 5
+			-4:00	Arg	AR%sT	1969 Oct  5
 			-3:00	Arg	AR%sT	1990 Jul
 			-3:00	-	ART	1991 Jul
 			-3:00	Arg	AR%sT	1992 Jul
-			-3:00	-	ART
+			-3:00	-	ART	1999 Oct  3 0:00
+			-4:00	Arg	AR%sT
 #
 # Mendoza (MZ)
 Zone America/Mendoza	-4:35:16 -	LMT	1894 Nov
@@ -166,7 +180,8 @@ Zone America/Mendoza	-4:35:16 -	LMT	1894 Nov
 			-4:00	-	WART	1991 Oct 15
 			-4:00	1:00	WARST	1992 Mar  1
 			-4:00	-	WART	1992 Oct 18
-			-3:00	-	ART
+			-3:00	-	ART	1999 Oct  3 0:00
+			-4:00	Arg	AR%sT
 
 # Aruba
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
@@ -411,7 +426,7 @@ Zone America/Porto_Acre	-4:31:12 -	LMT	1914
 			-5:00	Brazil	AC%sT	1988 Sep 12
 			-5:00	-	ACT
 #
-# Martin Vaz and Trinidade are like America/Noronha.
+# Martin Vaz and Trindade are like America/Noronha.
 
 
 # Chile
@@ -545,7 +560,8 @@ Rule	Para	1996	only	-	Mar	 1	0:00	0	-
 Rule	Para	1997	only	-	Feb	lastSun	0:00	0	-
 Rule	Para	1998	only	-	Mar	 1	0:00	0	-
 Rule	Para	1996	max	-	Oct	Sun>=1	0:00	1:00	S
-# IATA SSIM (1999-02) says lastSat, not lastSun; go with Shanks.
+# IATA SSIM (1999-02) says lastSat, not lastSun; (1999-09) reports no date;
+# go with Shanks.
 Rule	Para	1999	max	-	Feb	lastSun	0:00	0	-
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone America/Asuncion	-3:50:40 -	LMT	1890
diff --git a/timezone/zone.tab b/timezone/zone.tab
index b172d94..b65b6a3 100644
--- a/timezone/zone.tab
+++ b/timezone/zone.tab
@@ -1,4 +1,4 @@
-# @(#)zone.tab	1.17
+# @(#)zone.tab	1.18
 #
 # TZ zone descriptions
 #
@@ -234,7 +234,8 @@ MK	+4159+02126	Europe/Skopje
 ML	+1239-00800	Africa/Bamako	southwest Mali
 ML	+1446-00301	Africa/Timbuktu	northeast Mali
 MM	+1647+09610	Asia/Rangoon
-MN	+4755+10653	Asia/Ulan_Bator
+MN	+4755+10653	Asia/Ulaanbaatar	most locations
+MN	+4801+09139	Asia/Hovd	Bayan-Olgiy, Hovd, Uvs
 MO	+2214+11335	Asia/Macao
 MP	+1512+14545	Pacific/Saipan
 MQ	+1436-06105	America/Martinique
@@ -246,8 +247,9 @@ MV	+0410+07330	Indian/Maldives
 MW	-1547+03500	Africa/Blantyre
 MX	+1924-09909	America/Mexico_City	Central Time - most locations
 MX	+2105-08646	America/Cancun	Central Time - Quintana Roo
-MX	+2313-10625	America/Mazatlan	Mountain Time - most locations
+MX	+2313-10625	America/Mazatlan	Mountain Time - S Baja, Nayarit, Sinaloa
 MX	+2838-10605	America/Chihuahua	Mountain Time - Chihuahua
+MX	+2904-11058	America/Hermosillo	Mountain Standard Time - Sonora
 MX	+3232-11701	America/Tijuana	Pacific Time
 MY	+0310+10142	Asia/Kuala_Lumpur	peninsular Malaysia
 MY	+0133+11020	Asia/Kuching	Sabah & Sarawak